Ultra-violet absorption cross sections of isotopically substituted nitrous oxide species: 14N14NO, 15N14NO, 14N15NO and 15N15NO P. von Hessberg1, J. Kaiser2,*, M. B. Enghoff1, C. A. McLinden3, S. L. Sorensen4, T. Röckmann2, and M. S. Johnson1 1Department of Chemistry, University of Copenhagen, Copenhagen, Denmark 2Max-Planck Institute for Nuclear Physics, Atmospheric Physics Division, Heidelberg, Germany 3Air Quality Research Branch, Meteorological Service of Canada, Toronto, Ontario, Canada 4Synchrotron Radiation Research, Lund University, Lund, Sweden *now at Department of Geosciences, Princeton University, Princeton, New Jersey, USA
Abstract. The isotopically substituted nitrous oxide species 14N14NO, 15N14NO,
14N15NO and 15N15NO were investigated by
ultra-violet (UV) absorption spectroscopy. High precision cross sections
were obtained for the wavelength range 181 to 218nm at temperatures of 233
and 283K. These data are used to calculate photolytic isotopic
fractionation constants as a function of wavelength. The fractionation
constants were used in a three-dimensional chemical transport model in order
to simulate the actual fractionation of N2O in the stratosphere, and
the results were found to be in good agreement with field studies.
Citation: von Hessberg, P., Kaiser, J., Enghoff, M. B., McLinden, C. A., Sorensen, S. L., Röckmann, T., and Johnson, M. S.: Ultra-violet absorption cross sections of isotopically substituted nitrous oxide species: 14N14NO, 15N14NO, 14N15NO and 15N15NO, Atmos. Chem. Phys., 4, 1237-1253, doi:10.5194/acp-4-1237-2004, 2004.